Actually I don't do anything when on public transport - so to speak. I love watching the world go by, landscapes, cities, people, all those things that make travelling interesting, even on the shortest journeys. So I don't spend my time staring into a screen void, nor do I spend my time looking down towards my midriff, nor holding my hand out, nor having my ears blocked by bits of plastic. It may well be another form of zombieism in view of the missing cartwheels but at least the air can get to my face.